bluewave

Mild winters and humid summers have been the new normal following the global temperature jump in 15-16. It will be interesting to see how long it takes for another cold winter and less humid summer. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Season Mean Avg Temperature Missing Count 2018-2019 36.3 0 2017-2018 36.2 0 2016-2017 39.3 0 2015-2016 41.0 0 2014-2015 31.4 0 2013-2014 32.9 0 2012-2013 36.8 0 2011-2012 40.5 0 2010-2011 32.8 0 2009-2010 33.8 0

12z Euro delivers big on tropical moisture levels from Sunday through Thursday. Every day has max dewpoints at 75 degrees and above. Scattered convection each day except Monday which it has as the hottest. The cold front finally arrives on Friday drying things out for a time. Areas that get the most frequent convection will probably have some impressive rainfall totals and flooding through Thursday.

Area near Bethpage picked up an inch with training cells. Street flooding probably beginning in the usual spots.

Yeah, these boundaries often produce with 75 degree or higher dewpoints.

The 12z NAM has heat indices approaching 100 Monday in NJ with the very high humidity. https://www.instantweathermaps.com/NAM-php/conussfc.php?run=2019081712&time=INSTANT&var=HTIDXF&hour=057

The high dewpoints are back. Looks like the 20th day this year at JFK with a 75 degree or higher dewpoint. This is the now the 3rd highest number of days on record. Just an amazing record breaking high dewpoint surge since 2016. Kennedy Intl PTSUNNY 79 75 87 NE6 30.03S

The first few weeks of August are another example of less warm is the new cool. All our major stations are in the 0 to +1 range before the heat and humidity returns this week. This is why it’s so tough to see a below normal temperature departure anymore during the warm season. EWR...+0.3 NYC....+0.1 LGA....+1.1 JFK.....+0.4 ISP.....+0.9 BDR...+0.9 HPN....+0.9

Record breaking 500 mb ridge and jet streak near Alaska pumping the WAR. https://mobile.twitter.com/Climatologist49/status/1162384333832769537 The 500 mb height of 5980 m at Cold Bay, Alaska, is a station record and one of the highest values ever recorded in Alaska

Loss rate has slowed enough last few days for NSIDC extent to fall behind 2012 by 242k as of 8-15. .............2012......2019  8-13.....4.889......4.966.....77k behind 8-14.....4.724......4.970.....246k behind  8-15....4.679......4.921.....242k behind  8-16....4.619 8-17.....4.545 8-18.....4.520 8-19.....4.405  8-20.....4.313 NSIDC updated their projection for the September minimum. They are now calling for a 2nd place finish behind 2012. https://nsidc.org/arcticseaicenews/2019/08/dead-heat/ The ASINA team conducted a revised analysis of the likely course of the 2019 Arctic summer sea ice minimum, using rates of loss from several recent years. While sea ice extent is now above extent for the same date in 2012, overall our projection for the minimum is lower than estimated in our previous post. Using the average decline rate of the past 12 years, from 2007 to 2018, the 2019 minimum is estimated to be 3.75 million square kilometers (1.45 million square miles). If the 2012 decline pattern is applied from August 14 forward, sea ice reaches 3.44 million square kilometers (1.33 million square miles). This is still above the 2012 summer minimum extent of 3.39 million square kilometers (1.31 million square miles). However, nearly all of the recent rates of sea ice loss lead to 2019 being second lowest in ice extent, surpassing 2007 and 2016.

NSIDC daily extent holding steady on the 14th allowed 2019 to fall behind 2012 by 246k. But the area was able to move closer to 2012 than it has been over the last week. ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/seaice_analysis/Sea_Ice_Index_Daily_Extent_G02135_v3.0.xlsx .............2012......2019 8-13.....4.889......4.966.....77k behind 8-14.....4.724......4.970.....246k behind  8-15.....4.679  8-16.....4.619 8-17.....4.545 8-18.....4.520 8-19.....4.405  8-20.....4.313 NSIDC area https://cryospherecomputing.tk/

Root for a technological breakthrough that slows emissions before we get to that point. https://phys.org/news/2019-02-high-co2-destabilize-marine-layer.html At high enough atmospheric carbon dioxide (CO2) concentrations, Earth could reach a tipping point where marine stratus clouds become unstable and disappear, triggering a spike in global warming, according to a new modeling study. This event—which could raise surface temperatures by about 8 Kelvin (14 degrees Fahrenheit) globally—may occur at CO2 concentrations above 1,200 parts per million (ppm), according to the study, which will be published by Nature Geoscience on February 25. For reference, the current concentration is around 410 ppm and rising. If the world continues burning fossil fuels at the current rate, Earth's CO2 level could rise above 1,200 ppm in the next century. I think and hope that technological changes will slow carbon emissions so that we do not actually reach such high CO2 concentrations. But our results show that there are dangerous climate change thresholds that we had been unaware of," says Caltech's Tapio Schneider, Theodore Y. Wu Professor of Environmental Science and Engineering and senior research scientist at the Jet Propulsion Laboratory, which Caltech manages for NASA. Schneider, the lead author of the study, notes that the 1,200-ppm threshold is a rough estimate rather than a firm number. The study could help solve a longstanding mystery in paleoclimatology. Geological records indicate that during the Eocene (around 50 million years ago), the Arctic was frost free and home to crocodiles. However, according to existing climate models, CO2 levels would need to rise above 4,000 ppm to heat the planet enough for the Arctic to be that warm. This is more than twice as high as the likely CO2 concentration during this time period. However, a warming spike caused by the loss of stratus cloud decks could explain the appearance of the Eocene's hothouse climate. Stratus cloud decks cover about 20 percent of subtropical oceans and are prevalent in the eastern portions of those oceans—for example, off the coasts of California or Peru. The clouds cool and shade the earth as they reflect the sunlight that hits them back into space. That makes them important for regulating Earth's surface temperature. The problem is that the turbulent air motions that sustain these clouds are too small to be resolvable in global climate models. To circumvent the inability to resolve the clouds at a global scale, Schneider and his co-authors, Colleen Kaul and Kyle Pressel of the Pacific Northwest National Laboratory, created a small-scale model of a representative atmospheric section above a subtropical ocean, simulating the clouds and their turbulent motions over this ocean patch on supercomputers. They observed instability of the cloud decks followed by a spike in warming when CO2 levels exceeded 1,200 ppm. The researchers also found that once the cloud decks vanished, they did not reappear until CO2 levels dropped to levels substantially below where the instability first occurred. "This research points to a blind spot in climate modeling," says Schneider, who is currently leading a consortium called the Climate Modeling Alliance (CliMA) in an effort to build a new climate model. CliMA will use data assimilation and machine-learning tools to fuse Earth observations and high-resolution simulations into a model that represents clouds and otherimportant small-scale featuresbetter than existing models. One use of the new model will be to determine more precisely the CO2 level at which the instability of the cloud decks occurs.

Depends on the model. The Euro shifted the heaviest rains further to our south after The Sunday runs. It had very little for us by the Monday evening run. The upgraded GFS really struggled especially from 4-5 days out. It had the low cutting through upstate New York. Euro was always further south closer to reality.

97k daily decline for NSIDC extent. This places 2019 only 77k behind 2012 as of 8-13. Models indicate a continuation of the record breaking high pressure regime over the Arctic since May. Surface pressures are forecast to exceed 1040 mb around the Chukchi Sea region next 3-4 days. This would be at record levels for this time of year. ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/seaice_analysis/Sea_Ice_Index_Daily_Extent_G02135_v3.0.xlsx .............2012......2019 8-13.....4.889......4.966.....77k behind 8-14.....4.724 8-15.....4.679 8-16.....4.619 8-17.....4.545 8-18.....4.520 8-19.....4.405 8-20.....4.313

Plenty of unknowns concerning next winter at this time.  Will the raging Pacific jet relax? Will the record summer -NAO extend into winter? What will happen with ENSO? Will the amped up MJO continue for another winter? How will the extreme Arctic summer warmth and low sea ice impact the fall and winter circulation? How will the various record breaking SST patches evolve and impact the fall and winter pattern?

Same old story. Raging Pacific jet pumps the WAR. Looks like another record breaking jet streak coming up. Hopefully, we can see some relaxation of this regime by next winter.

This is a good write-up on the topic of this thread. https://www.sciencemag.org/news/2019/04/new-climate-models-predict-warming-surge For nearly 40 years, the massive computer models used to simulate global climate have delivered a fairly consistent picture of how fast human carbon emissions might warm the world. But a host of global climate models developed for the United Nations’s next major assessment of global warming, due in 2021, are now showing a puzzling but undeniable trend. They are running hotter than they have in the past. Soon the world could be, too. In earlier models, doubling atmospheric carbon dioxide (CO2) over preindustrial levels led models to predict somewhere between 2°C and 4.5°C of warming once the planet came into balance. But in at least eight of the next-generation models, produced by leading centers in the United States, the United Kingdom, Canada, and France, that “equilibrium climate sensitivity” has come in at 5°C or warmer. Modelers are struggling to identify which of their refinements explain this heightened sensitivity before the next assessment from the United Nations’s Intergovernmental Panel on Climate Change (IPCC). But the trend “is definitely real. There’s no question,” says Reto Knutti, a climate scientist at ETH Zurich in Switzerland. “Is that realistic or not? At this point, we don’t know.” That’s an urgent question: If the results are to be believed, the world has even less time than was thought to limit warming to 1.5°C or 2°C above preindustrial levels—a threshold many see as too dangerous to cross. With atmospheric CO2 already at 408 parts per million (ppm) and rising, up from preindustrial levels of 280 ppm, even previous scenarios suggested the world could warm 2°C within the next few decades. The new simulations are only now being discussed at meetings, and not all the numbers are in, so “it’s a bit too early to get wound up,” says John Fyfe, a climate scientist at the Canadian Centre for Climate Modelling and Analysis in Victoria, whose model is among those running much hotter than in the past. “But maybe we have to face a reality in the future that’s more pessimistic than it was in the past.” Many scientists are skeptical, pointing out that past climate changes recorded in ice cores and elsewhere don’t support the high climate sensitivity—nor does the pace of modern warming. The results so far are “not sufficient to convince me,” says Kate Marvel, a climate scientist at NASA’s Goddard Institute for Space Studies in New York City. In the effort to account for atmospheric components that are too small to directly simulate, like clouds, the new models could easily have strayed from reality, she says. “That’s always going to be a bumpy road.” Builders of the new models agree. Scientists at the National Oceanic and Atmospheric Administration’s Geophysical Fluid Dynamics Laboratory (GFDL) in Princeton, New Jersey—the birthplace of climate modeling—incorporated a host of improvements in their next-generation model. It mimics the ocean in fine enough detail to directly simulate eddies, honing its representation of heat-carrying currents like the Gulf Stream. Its rendering of the El Niño cycle, the periodic warming of the equatorial Pacific Ocean, looks “dead on,” says Michael Winton, a GFDL oceanographer who helped lead the model’s development. But for some reason, the world warms up faster with these improvements. Why? “We’re kind of mystified,” Winton says. Right now, he says, the model’s equilibrium sensitivity looks to be 5°C. Developers of another next-generation model, from the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, wonder whether their new rendering of clouds and aerosols might explain why it, too, is running hot, with a sensitivity in the low fives. The NCAR team, like other modelers, has had persistent problems in simulating the supercooled water found in clouds that form above the Southern Ocean around Antarctica. The clouds weren’t reflective enough, allowing the region to absorb too much sunlight. The new version fixes that problem. Late in the model’s development cycle, however, the NCAR group incorporated an updated data set on emissions of aerosols, fine particles from industry and natural processes that can both reflect sunlight or goose the development of clouds. The aerosol data threw everything off—when the model simulated the climate of the 20th century, it now showed hardly any warming. “It took us about a year to work that out,” says NCAR’s Andrew Gettelman, who helped lead the development of the model. But the aerosols may play a role in the higher sensitivity that the modelers now see, perhaps by affecting the thickness and extent of low ocean clouds. “We’re trying to understand if other [model developers] went through the same process,” Gettelman says. Answers may come from an ongoing exercise called the Coupled Model Intercomparison Project (CMIP), a precursor to each IPCC round. In it, modelers run a standard set of simulations, such as modeling the preindustrial climate and the effect of an abrupt quadrupling of atmospheric CO2 levels, and compare notes. The sixth CMIP is now at least a year late. The first draft of the next IPCC report was due in early April, yet only a handful of teams had uploaded modeling runs of future projections, says Fyfe, an author of the report’s projections chapter. “It’s maddening, because it feels like writing a sci-fi story as the first-order draft.” The ambitious scope of this CMIP is one reason for the delay. Beyond running the standard five simulations, centers can perform 23 additional modeling experiments, targeting specific science questions, such as cloud feedbacks or short-term prediction. The CMIP teams have also been asked to document their computer code more rigorously than in the past, and to make their models compatible with new evaluation tools, says Veronika Eyring, a climate modeler at the German Aerospace Center in Wessling who is co-leading this CMIP round. Such comparisons may help the modelers respond to the IPCC authors, who are peppering them with questions about the higher sensitivity, Gettelman says. “They’re asking us, what’s going on?” he says. “They’re pushing people. They’ve got about a year to figure this out.” In assessing how fast climate may change, the next IPCC report probably won’t lean as heavily on models as past reports did, says Thorsten Mauritsen, a climate scientist at Stockholm University and an IPCC author. It will look to other evidence as well, in particular a large study in preparation that will use ancient climates and observations of recent climate change to constrain sensitivity. IPCC is also not likely to give projections from all the models equal weight, Fyfe adds, instead weighing results by each model’s credibility. Even so, the model results remain disconcerting, Gettelman says. The planet is already warming faster than humans can cope with, after all. “The scary part is these models might be right,” he says. “Because that would be pretty devastating.”

Not that big a surprise the low track shifted south with the strongest -NAO of the summer. But we still have to watch for heavy rains north of the low like we are seeing now. Current radar New run Old run

It’s a false narrative that there is no objectivity left in climate science. Those names you mentioned have been trying to play down the influence of co2 to no avail. There have been major flaws detected in the papers that they like to cite in their arguments. Just look how poorly the global temperature forecast issued in the Curry stadium wave has performed. It’s been one new global high temperature record after another following the publication of that paper in 2013. https://www.news.gatech.edu/2013/10/10/‘stadium-waves’-could-explain-lull-global-warming “The stadium wave signal predicts that the current pause in global warming could extend into the 2030s," said Wyatt, an independent scientist after having earned her Ph.D. from the University of Colorado in 2012. Curry added, "This prediction is in contrast to the recently released IPCC AR5 Report that projects an imminent resumption of the warming, likely to be in the range of a 0.3 to 0.7 degree Celsius rise in global mean surface temperature from 2016 to 2035." Curry is the chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology. From Katharine Hayhoe: https://m.facebook.com/katharine.hayhoe/posts/1915202578704620 https://mobile.twitter.com/khayhoe/status/1149134713648484352?lang=en We re-analyzed 38 studies that questioned whether climate is changing and/or humans are responsible, and found an error in each that, when corrected, brought them in line with the scientific consensus. Our study's been downloaded >100k times now! https://www.theguardian.com/environment/climate-consensus-97-per-cent/2015/aug/25/heres-what-happens-when-you-try-to-replicate-climate-contrarian-papers

Small daily rise in NSIDC extent of 19k. This puts 2019 behind 2012 by -92k as of the 11th. NSIDC extent    Date....2012......2019....2019 difference  8-4......5.990.... .5.762.....+228k lead 8-5......5.768......5.596.....+172k lead  8-6......5.632......5.510......+122k lead  8-7......5.467......5.388......+79k lead 8-8......5.256.....5.390......-134k behind 8-9......5.088......5.259......-171k behind  8-10....5.118......5.093......+25k ahead  8-11....5.021......5.113.......-92k behind 8-12.....4.938 8-13.....4.889 8-14.....4.724 8-15.....4.679 8-16.....4.619 8-17.....4.545 8-18.....4.520 8-19.....4.405 8-20.....4.313

Departures should get an eventual boost as the WAR makes a return next week.

This site has it. https://cryospherecomputing.tk/

Flash flood and severe potential along the track of the low. Probably need several more model runs to pin down the exact track.

48 days is the 8th longest streak. It’s a dense rank by number of days like the NWS OKX uses. The difference between the RANK and DENSE_RANK functions is in how values are assigned to rows following a tie. In case of tie of two records for the first position, the third record that follows to the tie in order will be considered third position if you use RANK, while the third record that follows the tie is considered second position if you choose DENSE_RANK.

Low of 58 at Islip ends the 8th longest run of 60 and above minimum temperatures. Number of Consecutive Days Min Temperature >= 60 for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Run Length Ending Date 1 63 1967-08-31 2 62 2015-08-28 3 61 2003-08-23 4 58 2005-09-05 5 55 2006-08-11 - 55 1994-08-05 6 52 2014-08-14 7 50 2016-08-22 8 48 2019-08-10 - 48 2008-08-08 9 46 1988-08-18 10 45 2018-08-23 - 45 2013-08-04

Very large daily NSIDC decline of 166k puts 2019 back in a narrow lead over 2012 by +25k. ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/seaice_analysis/Sea_Ice_Index_Daily_Extent_G02135_v3.0.xlsx NSIDC extent    Date....2012......2019....2019 difference 8-4......5.990.... .5.762.....+228k lead 8-5......5.768......5.596.....+172k lead  8-6......5.632......5.510......+122k lead 8-7......5.467......5.388......+79k lead 8-8......5.256.....5.390......-134k behind 8-9......5.088......5.259......-171k behind  8-10....5.118......5.093......+25k ahead 8-11....5.021